docs: def com_google_fonts_check_maxadvancewidth(ttFont):
    """MaxAdvanceWidth is consistent with values in the Hmtx and Hhea tables?"""
    hhea_advance_width_max = ttFont['hhea'].advanceWidthMax
    hmtx_advance_width_max = None
    for g in ttFont['hmtx'].metrics.values():
      if hmtx_advance_width_max is None:
        hmtx_advance_width_max = max(0, g[0])
      else:
        hmtx_advance_width_max = max(g[0], hmtx_advance_width_max)
  
    if hmtx_advance_width_max != hhea_advance_width_max:
      yield FAIL, ("AdvanceWidthMax mismatch: expected {} (from hmtx);"
                   " got {} (from hhea)").format(hmtx_advance_width_max,
                                                 hhea_advance_width_max)
    else:
      yield PASS, ("MaxAdvanceWidth is consistent"
                   " with values in the Hmtx and Hhea tables.")